Polymer film, preparation method thereof, and polymer film laminate comprising the same

Abstract

The present disclosure relates to a polymer film, a preparation method of the same, and a polymer film laminate. Specifically, it relates to a new type of polymer film, which is thin and exhibits excellent absorption performance while having excellent flexibility and mechanical properties. In addition, the polymer film is free from scattering or leaking, and does not require an auxiliary substance such as pulp, so that products can be made thinner and the manufacturing process and costs may be reduced. In addition, the present disclosure also relates to a preparation method of the above-described polymer film, and a polymer film laminate including the new type of polymer film.

The invention claimed is: 
     
       1. A polymer film comprising
 a polymer obtained by polymerizing an acrylic acid-based monomer having at least partially neutralized acidic groups, 
 wherein a thickness of the film is 0.001 mm or more and 0.5 mm or less, 
 the polymer film comprises a pattern having a hole structure penetrating the film, and 
 an elongation calculated by the following Equation 1 is 100% or more:
   Elongation (%)=( L   1   −L   0 )/ L   0 *100  [Equation 1]
 
 
 in the Equation 1, 
 L 0  is an initial gauge length, and 
 L 1  is a gauge length at fracture when the specimen is pulled at a rate of 0.5 mm per minute,
 wherein the acrylic acid-based monomer is a compound represented by the following Chemical Formula 1:
   R 1 —COOM 1   [Chemical Formula 1]
 
 
 in Chemical Formula 1, 
 R 1  is a C2 to C5 alkyl group having an unsaturated bond, and 
 
 M 1  is a hydrogen atom, a monovalent or divalent metal, or an ammonium group. 
 
     
     
       2. The polymer film of  claim 1 ,
 wherein a maximum diameter of each hole structure is 1 mm or more and 15 mm or less. 
 
     
     
       3. The polymer film of  claim 1 ,
 wherein a distance between holes of the pattern is 1 mm or more and 10 mm or less. 
 
     
     
       4. The polymer film of  claim 1 ,
 wherein a total area of the hole structure is 15% or more and 80% or less of an area of the film. 
 
     
     
       5. The polymer film of  claim 1 ,
 wherein a weight per unit area is 100 g/m 2  or more and 210 g/m 2  or less when the thickness of the film is 0.2 mm. 
 
     
     
       6. The polymer film of  claim 1 ,
 wherein a centrifuge retention capacity (CRC) of the film is 30 g/g or more, 
 wherein an absorption rate of the film is 10 seconds or more and 50 seconds or less, and 
 the absorption rate is a time taken until all of a 0.9 wt % saline is absorbed when the polymer film is cut to a size of 10 cm in width*25 cm in length to have smooth cut surface, a non-woven fabric with the same size is attached above and below the polymer film, a cylindrical plastic tube with an inner diameter of 60 mm is placed in a center of the polymer film, and then 80 ml of the saline is added at a rate of 15 ml/s using a funnel. 
 
     
     
       7. The polymer film of  claim 1 ,
 wherein an absorption rate of the film is 10 seconds or more and 50 seconds or less, and the elongation is 100% or more and 550% or less. 
 
     
     
       8. A product comprising the polymer film of  claim 1 ,
 wherein the product is any one of hygiene products, wallpaper with moisture absorption and desorption property, absorbent pads for food, pee pads for pets and medical bands. 
 
     
     
       9. A preparation method of the polymer film of  claim 1 , comprising:
 preparing a monomer composition by mixing an acrylic acid-based monomer having at least partially neutralized acidic groups, a cellulose-based thickener, a moisturizing agent, a polymerization initiator, and a solvent; 
 forming a monomer composition film by casting the monomer composition on a substrate; 
 forming a hydrogel polymer film by irradiating heat or light while drawing the monomer composition film; 
 drying the hydrogel polymer film to form a dried polymer film; and 
 forming a polymer film by forming a pattern on the dried polymer film. 
 
     
     
       10. The preparation method of the polymer film of  claim 9 ,
 wherein the cellulose-based thickener is at least one selected from the group consisting of nanocellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, and hydroxypropylmethylcellulose. 
 
     
     
       11. The preparation method of the polymer film of  claim 9 ,
 wherein the moisturizing agent is at least one selected from the group consisting of glycerin; diglycerin; propylene glycol; butylene glycol; sorbitol; polyethylene glycol; polyglycerin-3; polyglycerin-6; polyglycerin-10; and polyglyceryl-10 distearate and a derivative thereof (C3 to C18); citric acid; triethylcitrate, methylcitrate, sodium citrate, and trisodium 2-methylcitrate. 
 
     
     
       12. The preparation method of the polymer film of  claim 9 ,
 wherein the cellulose-based thickener is contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of a solid content in the monomer composition. 
 
     
     
       13. The preparation method of the polymer film of  claim 9 ,
 wherein the moisturizing agent is contained in an amount of 5 to 70 parts by weight based on 100 parts by weight of the acrylic acid-based monomer. 
 
     
     
       14. The preparation method of the polymer film of  claim 9 ,
 wherein a viscosity at 25° C. of the monomer composition is 100 mPa· s or more. 
 
     
     
       15. The preparation method of the polymer film of  claim 9 ,
 wherein the forming the polymer film is performed in a Print and Cut method. 
 
     
     
       16. A polymer film laminate comprising:
 a non-woven fabric; and 
 the polymer film of  claim 1  being both above and below the nonwoven fabric. 
 
     
     
       17. The polymer film laminate of  claim 16 ,
 wherein a weight per unit area of the non-woven fabric having a thickness of 0.25 mm is 60 g/m 2  or less. 
 
     
     
       18. The polymer film laminate of  claim 16 ,
 wherein a maximum diameter of the hole structure is 1 mm or more and 15 mm or less, 
 wherein a distance between holes of the pattern is 1 mm or more and 10 mm or less, and 
 wherein a total area of the hole structure is 20% or more and 80% or less of an area of the polymer film. 
 
     
     
       19. The polymer film laminate of  claim 16 ,
 wherein a weight per unit area of the polymer film having a thickness of 0.2 mm is 100 g/m 2  or more and 210 g/m 2  or less. 
 
     
     
       20. The polymer film laminate of  claim 16 ,
 wherein centrifuge retention capacity (CRC) is 30 g/g or more, 
 wherein an absorption rate is 10 seconds or more and 30 seconds or less, and 
 the absorption rate is a time taken until all of 0.9 wt % saline is absorbed when the polymer film laminate is cut to a size of 10 cm in width*25 cm in length to have smooth cut surface, a cylindrical plastic tube with an inner diameter of 60 mm is placed in a center of the polymer film laminate, and then 80 ml of the saline is added at a rate of 15 ml/s using a funnel.